1. Field of the Invention
The invention relates generally to exhaust systems for internal combustion engines and in particular to an improved exhaust gas control device that can selectively conduct the exhaust gases to a muffler or directly to the atmosphere as desired.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 And 1.98
Muffler systems are well known in the art and are placed on internal combustion engines to enable the engines to run more quietly. However, it is also well known that such systems create back pressure that lessens the efficiency of the engine.
Consequently, many devices have been developed to selectively divert such exhaust gases from the muffler directly to the atmosphere. This allows the engine to operate more efficiently but does increase the noise of the engine.
Such devices in the prior art have always used flapper valves or butterfly valves. For instance, in U.S. Pat. No. 5,452,578, a housing is placed in the exhaust manifold with a diverter plate or flapper valve that, in a first position, lies flat below the exhaust pipe but, when activated, pivots at the base upwardly to divert the incoming exhaust gases outwardly to the atmosphere. Because of the construction of such valve, there is leakage around it and consequently the greatest efficiency is not obtained.
Further, in U.S. Pat. No. 5,401,001, the exhaust control valve is in the form of a butterfly valve that, when vertical, causes the exhaust gases to flow in one path and, when horizontal, allows exhaust gas to flow through a second path. This device is sealed by a complex arrangement of several parts to event escape of exhaust gases.
It would be desirable to have an exhaust control valve that seals off one path to prevent exhaust gases from escaping or alternatively to open a second path and allow them to escape. Such a device can be provided with the use of a gate valve rather than a flapper valve or butterfly valve.